Safety pilot burners

Abstract

In a gas burning installation a pilot burner is provided with means to control the amount of atmospheric air introduced into the fuel gas in the burner tube, the means comprising a restriction in the tube upstream of where air enters and a variable choke downstream of where air enters, which choke affects the resistance to the flow of gas along the tube.

I claim: 
     
       1. Apparatus for inducing ambient air into a fuel gas stream and comprising a duct for said stream, which duct has at least one port through which ambient air may enter the duct and a constriction upstream of the at least one port with reference to the direction of flow of the stream, and means located along the duct downstream of said at least one port, for varying the resistance to the flow of gas and also the induction of said ambient air, said resistance varying means comprising a choke adjustable within said duct for controlling the effective internal cross-section thereof, said choke comprising a pin arranged for variable projection into the interior of said duct through an opening therein, wherein the variation of the projection of said pin is effected by means of a bi-metallic strip.